package com.forum.ajax.homepage;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.acl.Group;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.json.JSONException;
import org.json.JSONObject;

import com.forum.domain.Groups;
import com.forum.domain.GroupsDAO;
import com.forum.domain.Ucg;
import com.forum.domain.UcgDAO;
import com.forum.domain.User;
import com.forum.domain.UserDAO;

public class RandomGroups extends HttpServlet {

	private final int create_count = 20;

	/**
	 * Constructor of the object.
	 */
	public RandomGroups() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		PrintWriter out = response.getWriter();
		
		int userid = Integer.parseInt(request.getParameter("id"));
		UserDAO userDAO = new UserDAO();
		User user = userDAO.findById(userid);
		

		GroupsDAO groupsDAO = new GroupsDAO();
		UcgDAO ucgDAO = new UcgDAO();
		
		List<Groups> grouplist = new LinkedList<Groups>();

		List<Groups> allGroups = groupsDAO.findAll();

		int count = 0;
		if (allGroups.size() > this.create_count)
			count = this.create_count;
		else
			count = allGroups.size();

		Set<Integer> myset = new LinkedHashSet<Integer>();
		while (myset.size() < count) {
			myset.add((int) (Math.random() * count));
		}
		
		Iterator iterator = myset.iterator();
		while(iterator.hasNext())
		{
			int index = (Integer)iterator.next();
			Groups group = allGroups.get(index);
			List<Ucg> ucglist = ucgDAO.findByProperty("groups", group);
			boolean should_add = true;
			for(int i = 0 ; i < ucglist.size() ; i++)
			{
				if(ucglist.get(i).getUser() == user)
				{
					should_add = false;
					break;
				}
			}
			
			if(should_add == true)
			{
				grouplist.add(group);
			}
		}
		
		JSONObject json = new JSONObject();
		
		try {
			json.accumulate("count", grouplist.size());
			
			for(int i = 0 ; i < grouplist.size() ; i ++)
			{
				Groups group = grouplist.get(i);
				JSONObject groupJson = new JSONObject();
				groupJson.accumulate("id", group.getId());
				groupJson.accumulate("name", group.getName());
				groupJson.accumulate("intro", group.getIntroduction());
				groupJson.accumulate("owner", group.getUser().getNickname());
				groupJson.accumulate("time", group.getBuilddate().toGMTString());
				json.append("group", groupJson);
			}
			
			out.print(json);
			
		} catch (JSONException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			out.print("error");
		}

	}

	/**
	 * The doPost method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to
	 * post.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
	}

	/**
	 * Initialization of the servlet. <br>
	 * 
	 * @throws ServletException
	 *             if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}
